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Homework Problem 14.55b

Posted: Tue Feb 20, 2018 11:30 pm
by Lily Guo 1D
"A 1.0 m NiSO4(aq) solution was electrolyzed by using inert electrodes. Write (a) the cathode reaction; (b) the anode reaction. (c) With no overpotential or passivity at the electrodes, what is the minimum potential that must be supplied to the cell for the onset of electrolysis?"

The solutions manual has the anode reaction as 2H2O (l) --> O2 (g) + 4H+ (aq) + 4e-, which has an E°= +1.23V, but why is the anode reaction not the oxidation of the SO4 2- ion if that reaction has a lower E° = +0.17V? The book says to choose the oxidation reaction with the least positive/most negative standard reduction potential (E° value), so I'm a little confused.

Re: Homework Problem 14.55b

Posted: Tue Feb 20, 2018 11:35 pm
by Eli Aminpour 2K
In electrolysis, an electric current is passed through the substance. It is different than the chemical reaction that occurs in an galvanic cell. That is why you focus on the most positive standard reduction potentials

Re: Homework Problem 14.55b  [ENDORSED]

Posted: Fri Mar 16, 2018 10:31 am
by Chem_Mod